


A Star in the Morning Sky

by WaterDarkE



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alpha/Beta/Omega Dynamics, Implied/Referenced Rape/Non-con, M/M, Omega Verse, Parent-Child Relationship, Past Rape/Non-con, Unplanned Pregnancy
Language: English
Status: In-Progress
Published: 2019-11-10
Updated: 2019-11-12
Packaged: 2021-01-26 15:30:55
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,167
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21376396
Author URL: https://archiveofourown.org/users/WaterDarkE/pseuds/WaterDarkE
Summary: When Byleth was recruited into Garrech Mach Monastery, he brought a small child in tow whose name was Kamui.The resemblance between the two was undeniable and the bond between the two was extremely strong. But in a world filled with alphas, omegas, and betas, there were several possibilities. However, as Byleth’s own reputation grew, most unseeming rumors died down, even while Byleth took a short break from teaching at least once a month to take care of “important business and affairs.” After all, Byleth was a beta, but an abnormally powerful one.One day, both Claude and Dimitri discover Byleth’s secret on his day off. In a hidden area of the monastery, forbidden from students, they found Kamui looking for her mother after getting lost. Wondering who the mother was, they look for Byleth for answers who locked himself in a room, believed to be handling an unusual condition, an abnormally intense rut where he would go berserk if in the presence of his students. Yet, they open the door and discover the truth.What sort of bond will form between the three, as in that moment, Byleth realized he had two fated mates, and for Dimitri and Claude, that Byleth was their soul mate?[Discontinued]
Relationships: Dimitri Alexandre Blaiddyd/My Unit | Byleth/Claude von Riegan
Comments: 14
Kudos: 51





	1. Discovering a Vital Secret

**Author's Note:**

> This fanfic was partially inspired by the manga, Kiraide Isasete.

_ “Father, I’m going to raise her myself. It is not her fault that she was born. She is the most innocent one. Her name is Kamui, so she can decide her own fate, even if she must fight against the entire world depending on her secondary gender. Throughout all of her turmoil, I will be with her. And I hope you will be too, just like how you raised me after Mother passed away.” _

* * *

It was a rainy day when Byleth became a professor at Garrach Mach Monastery, after saving the current leaders of the three houses from bandits. Edelgard of the Black Eagles, Dimitri of the Blue Lions, and Claude of the Golden Deer. After some careful deliberation, Byleth became a professor of the Golden Deer, and brought his child with him. Introducing her as Kamui, Byleth told everyone that a distant relative brought her into his care due to unusual circumstances. It was easy to see that the two were related, sharing the same eye color, hair color, and stoic expressions, even if Kamui was far more expressive than her guardian. The current students and faculty could easily see how strong their bond was, enough that they could be mistaken as father and daughter. When asked about their relationship, Byleth never gave them a clear answer, saying that it was a secret to protect Kamui’s privacy and future. Even questioning Jeralt, Byleth’s father, led to no answers and only more questions.

Byleth quickly gained an incredibly positive reception from both current students and faculty. Even with his youth, only a few years older than most of the students, his lectures were unparalleled for being both practical and engaging. Seen as a general jack-of-all trades, there was very little that Byleth did not know. Often, his students would visit his office hours for questions that they had, even for different classes and Byleth would answer them easily and with great efficiency. For his students, Byleth would put in his all to support their growth into adulthood and to prepare them for the trials that would come ahead. Due to his students putting him in high regard, students from the Blue Lions and the Black Eagles also sought his guidance and he tried his best to attend to their needs, while prioritizing his own students and Kamui.

In his free time, he would play with Kamui around the monastery, reading her books, going on walks with her, and helping her study books and subjects at her level, and it became understood that she was extremely bright for her age. When Byleth was busy, he left Kamui with Jeralt who would take care of her with incredible care and diligence, to the surprise of the faculty and the students. “What do you take me for?” Jeralt would often say. “I raised Byleth with my wife and after she passed. Of course I know how to take care of young children.” The older, gruff man doted on Kamui as if he was her grandfather, sometimes giving her sweets and making sure she dressed warmly when it became colder.

Byleth, to the knowledge of everyone, was a beta. After all, it was what he said himself. In a world ruled by both the caste and hierarchy, but also by the prominence of secondary genders of alpha, omega, and beta, the Garrech Mach Monastery was known for treating all of its students and faculty equally, no matter their secondary gender. But, discrimination existed even as faculty and students tried their best to stamp it out as having traditional values linked to secondary genders was seen as outdated and old-fashioned. So, Garrech Mach Monastery was revolutionary in its time, for its values, its education, and also as the school to attend for those wanting to be successful in the future, whether in a certain profession or in leading their families as respective heirs to respective crests. Edelgard, Dimitri, and Claude were well known for being alphas, but also people who treated those in their respective houses fairly and equally, without discrimination or unfair judgement.

Yet, everything changed on a snowy day.

* * *

In the early hours of the morning, Claude woke up to the sounds of someone crying. It sounded like a young girl, trying to be quiet, but her voice kept echoing throughout the empty halls. Removing the covers of his bed, he quickly dressed into some warmer clothing and left his room. While walking down the hallway, he saw heavy snow falling, enough for a giant storm. 

“Looks like class will be canceled today.”

As he approached the voice, he spotted Dimitri looking around.

“Why are you up so early? I imagined that you would be the type to sleep in? Like Edelgard.”

Dimitri shook his head. “My nightmares kept me awake tonight.” Claude could tell from the dark circles under his eyes.

“Do you think the crying is coming from Kamui, Teach’s kid?”

“Most likely.” Dimitri looked to be in deep thought. “I can’t imagine that it would be anyone else.”

“So, why don’t we figure out why she is crying.” Claude gave Dimitri his characteristic smirk. “Gentlemen like us should help ladies in need.”

Investigating the nearby area, they walked closer to the church area of the monastery. Because it was before waking hours, it was completely empty besides the two of them and the young girl’s voice. Trying to gauge where the source of the noise was, they found themselves approaching the side of the church area, in one of the side rooms. As empty as it was, it looked completely normal, outside of being decorated with paintings.

Searching the room, Claude alerted Dimitri by gesturing him to come over. “Dimitri, I think this is the key.” He pointed to a small painting of a fearsome dragon, but compared to the other paintings, it was tilted. Not too much to be significant, but to an observant eye, it was noticeable. Claude tried tilting the painting more, but it seemed to be stuck in place. Instead, he turned it the other way and heard a click and gears turning. “Just like I thought.”

And just like magic, the wall behind the painting slide to the side to reveal a hidden door and a set of stairs. The sound of crying seemed to become even louder. With a feeling of slight apprehension, they opened and closed the door behind them, hearing the wall slide back into place, and walked downwards.

After walking for some time, they found themselves in a large library, full of old books and antiques which seemed to have been there for tens to hundreds of years. It was all kept in good condition. Right as they entered, they spotted Kamui sitting on the floor, crying as she tried to wipe the tears from her face. “Mommy! Mommy! I don’t know where you are!”

Hearing the sound of footsteps, she turned to the sound, and her face brightened. “Big Brother Claude! And Big Brother Dimitri!” Getting up, she grabbed both of their hands. “Please help me find Mommy.”

“Sure we will.” Claude patted her head as Dimitri took out a handkerchief from his pocket and wiped her tears away. “We’ll help you find her. Do you know where she is?”

Kamui shook her head. “Mommy wasn’t feeling good, so they told me to fill up a bottle of water. Once I left, I got it filled up, but forgot how to get back.” She sniffled for a bit. “Mommy tells me I’m smart all the time, so me getting lost makes me feel so sad.”

“It’s okay. Your mommy must be nice.”

“They are!” She beamed at them before her eyes widened. “Ohh! I remember now. Mommy told me to say this if I forget where she is.” She closed her eyes and recited what seemed to be like a simple riddle:

_ “My beautiful daughter, bright as a button, _

_ If you find that you have lost your way, _

_ Go straight down the hallway, _

_ Make a right at the windy tree,  _

_ Make a left at the blooming flower, _

_ At the door with the moon, _

_ I will be waiting for you.” _

Dimitri turned to Claude. “This seems simple enough.”

“Definitely,” Dimitri replied as he nodded in response. “Why don’t we follow this riddle and find your mother.”

Walking straight down the hallway, they made a right near the painting of a windswept tree, a left near the painting of a field of blooming flowers, and soon arrived at a door with a moon in the center. An intoxicating smell came from the room, like that of an omega in heat, but it seemed different somehow. Like a comforting smell or smelling like a warm embrace of a beloved one.

Dimitri’s heart began to race, as an unexpected feeling of arousal filled his entire body. “What is this?!” He frantically grabbed a bottle of suppressants from his pocket and chewed them frantically. He noticed Claude’s face twisted in discomfort, as he too struggled to maintain his control and take his suppressants. Carrying suppressants was mandatory for unexpected situations.

Kamui opened the door, and they saw an unexpected sight and gagged at the intense scent that overcame them. .

Byleth was lying down in a bed, profusely sweating, as Kamui handed him a bottle of water. “Mommy, I got lost and Big Brother Claude and Big Brother Dimitri helped me find my way back.”

His eyes widening, Byleth’s soft expression turned to almost a glare and a cold feeling, completely different from his normal stoic expression during the school day, as he sat up, trying to maintain his composure. And then sighed.

“Thank you for helping Kamui. And out of all the people in this school, you two were the students who discovered my secondary gender first.” Byleth gestured Kamui to slip under the covers with him and get some rest.

“As you can see, I’m an omega, not a beta as you all expected me to be. Obviously, you couldn’t tell because I take the strongest suppressants possible. But during my most intense heat days, they don’t work and I have to take refuge here, with the help of Rhea and the faculty covering for my absence. Since I can tell you both have questions, but I’m not in the state to properly speak, and neither are you.” Byleth grabbed the Sword of the Creator from the side of his bed and pointed it at the two of them. “Speak to me once I have returned on Friday, after class and in my office at exactly 6 PM. Do not speak of this to anyone. Or else… You will face a punishment where you would have wished that you have died.” Byleth’s menacing tone confirmed just how serious he was.

Dimitri and Claude both nodded before abruptly leaving the room, and closing the door. Returning to their rooms, they couldn’t help but mull over the strange events that have just occurred to them.

While, Byleth could only wait until their heat becoming more manageable, and knowing all too well that everything could go very wrong. As he felt their very soul wanting to be impregnated by both Claude and Dimitri.

“Having two fated mates… this could be a problem.”

* * *

On the upcoming Friday, after classes and close to dinner time, Dimitri and Claude approached Byleth’s office. Dimitri tentatively knocked as he heard Byleth say, “Come in.”

And together, they walked in, seeing Byleth sit behind his desk, two chairs nearby it.

“Sit down then.” As they took a seat, Byleth crossed their legs and arms and looked at them straight in the eyes.

“So, what do you want to ask me?”


	2. Heartbeat and Understanding

**Summary for the Chapter:**

> Byleth speaks with both Claude and Dimitri in a more intimate fashion, and is met with mutual understanding. And then, it is time to eat.

**Notes for the Chapter:**

> Thank you guys so much for commentating on my first chapter. ;-;. It means so much to me. I didn't realize that such words could be so invigorating. So here is a more calm chapter.

_When Kamui was born, what Byleth noticed the most was not only was she warm, but she had a heartbeat. Compared to himself who lost it long ago due to special circumstances, but was still alive. Because of that very fact, he had felt very alone in his life, and believed himself to be not only a freak of nature, but also to be a monster._

_Cradingly her in his arms, as he caressed her curly hair, tears ran down his face._

_“Kamui, thank you for being born. I realize now that I’m human, just like you.”_

* * *

On the upcoming Friday, after classes and close to dinner time, Dimitri and Claude approached Byleth’s office. Dimitri tentatively knocked as he heard Byleth say, “Come in.”

And together, they walked in, seeing Byleth sit behind his desk, two chairs nearby it.

“Sit down then.” As they took a seat, Byleth crossed their legs and arms and looked at them straight in the eyes.

“So, what do you want to ask me?”

* * *

Dimitri was the first to speak, noticing immediately a change in the surroundings. Around Byleth was a sort of flowery scent, that was barely noticeable. Sort of like a woman’s perfume, but he knew that his professor was not the type to wear perfume. And somewhat hidden around his neck was a silver necklace or collar of some sort, underneath his usual professor uniform. 

“Professor, why are you hiding that you are Kamui’s mother?” He emphasized the final word. “You do know that the Garrech Mach Monastery is known for its fair treatment of all secondary genders, for it is one of its most important and valued characteristics.”

“Well, that should be obvious.” Byleth glanced at Claude who nodded understandingly. “Discrimination always exists, even under the guise of equality. Maybe it is not practiced by you or by me. But with how integrated in society discrimination against omegas is in this country, if I am not careful, it would bear its fangs. I know that far too well.” His tone of voice had a feeling of weariness, an exhaustion that sunk through his very bones. “After all, I was raped by a comrade of mine when I was sixteen, right after I presented as an omega.” At the word “raped,” his voice noticeably shook before he composed himself. “My comrade apologized afterwards, saying that he could not control himself. But I can never forget the trauma attached to it. Feeling like my body, and my soul was violated against my will. I felt disgusted, and still do to this day. Those memories have become engraved in my mind, forever.”

There was a silence that filled the room, before Claude took a deep breath and spoke.

“Teach, you were brave to have decided to give birth to Kamui. You really are amazing. I can only commend you for that.”

“Thanks Claude. You have always been understanding of me.” Byleth smiled faintly, and the flowery scent in the room gave off a feeling of warmth.

“But, let’s get back to it.” Byleth became serious again. “Have you both realized that I’m not just a fated mate for one person, but both of you?” He sighed at his own words. “This is troublesome.”

Dimitri nodded to confirm, along with Claude. 

“Professor, I knew it very well. Fated pairs were believed to only be a myth and regarded as folklore because of the rarity of meeting that person of destiny. But once I saw you in heat, I knew you were the one. My heart tells me this.” Chuckling at his own words, putting a hand over his heart. “I don’t think I could have said such cheesy words, but I have. And what about you, Claude?”

“I agree Teach, with Dimitri. You are the one for me.” He looked at Dimitri in a friendly manner. “It’s disappointing that I would have to share you with someone else, but at least it’s someone I know and trust. Unlike Edelgard,”

“I’m glad you are both understanding.” Byleth smiled even more brightly. “This turned out better than I expected. But you must understand that I cannot bond with anyone yet. Especially since I don’t know either of you as well as I would like.” He wrapped his arms around his abdomen. “I am not nearly as innocent as I used to be. After all, I have Kamui. But maybe, in a more peaceful time, when the wind of conflict ends. I can feel it in my bones that something will happen in the future, something that will change the world.”

He gently grabbed one of Dimitri and one of Claude’s hands, and clasped together. 

“So please, help me. Not only protect myself, but also Kamui.”

Claude was the first to stand, and then wrap his arms around Byleth. Whispering in his ear, he said, “I swear I will, Teach.” Before backing away, ready to head off. “I probably will get a bite to eat. Good night.” And saluted before making his way out.

Dimitri, on the other hand, more awkwardly shook Byleth’s hand. “I have a long way to go to Professor. But I promise I won’t let you down. You can at least count on that.”

* * *

As he turned to open the door, he saw Kamui standing by it, waiting for her mother. And Jeralt closely behind her, probably keeping an eye on her as usual.

“Is Mommy done?”

“He is.” Dimitri fondly ruffled Kamui’s fluffy hair, met by Jeralt’s knowing gaze.

“I guess you, and that young fella in the yellow are Kamui’s fated mates. Just like me and my wife way back then.” Jeralt looked into the distance, lost in thought, before clearing his throat with a cough.

“If either of you make Byleth cry, I will make sure that you both receive what you deserve.” He said it in a way that was extremely calm, but also, extremely menacing, with cold, fearsome eyes. It was easy to see that both he and his son had similar ways of being angry. And then he shrugged.

“Well, besides that, me and Kamui were getting hungry. Byleth, why don’t you stop being cooped up in your office and join us in the mess hall.”

“Of course Father.” Byleth stood up, and locked his office behind him. “I was feeling hungry too.” Taking the opportunity to hold Kamui’s hand, as she squeezed back. “So Kamui, what would you like to eat today?”

“I want to eat a cheese gratin!” she said cheerfully, the enthusiasm in her voice contagious. 

“Ohh! You mean, the Gratier Cheese Gratin?” She nodded at this. “It’s one of your favorites, isn’t it?” Which she replied to with a beam.

As they made their way to the mess hall, Byleth looked at Dimitri. “How about you?”

“The same as Kamui.” He blushed softly at this. “That gratin dish is one of my favorites.”

“I see.” So, Byleth made a mental note of this. 

“If I can remember, Ashe should be cooking today. He is very good at this, so I’ll have to make sure he makes plenty of the cheese gratin. I’m looking forward to it.”

And they continued walking with gusto, as the snow kept falling outside.

* * *

Soon, it would be the night of the long awaited ball, and visiting the Goddess Tower.

**Notes for the Chapter:**

> Since I have more free time, I will try to update this as much as I can. The next chapter covers the ball and Goddess Tower, and hopefully some more Kamui fluff since you guys seemed to enjoy that. ;D

**Author's Note:**

> Let me know if you are interested in me continuing this fic~


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